Spring-jack switch.



PATENTED Nov. 13, 1900.

vNo. 006,040.

0. H. NORTH. y SPRING JACK SWITCH.l APPLIOLTION FILED 000.011.1001.

rHENnRms PETERS cc., wAsmNaToN. D. c.

UNITED STATES PATENT OFFICE.'

CHARLES H. NORTH, OE CLEVELAND, OHIO, ASSICNOR TO THE NORTH ELECTRIC COMPANY, OE CLEVELAND, OHIO, A CORPORATION or OHIO. f

SPRING-JACK SWITCH.

Patented Nov. 13, 1906.

Y To a/ZZ whom t may concern.-

Beit known that I, CHARLES H. NORTH, a citizen ofthe United States of America, and a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Spring- Jack Switches, of which the following is a specification.

My invention relates to improvements in spring-jack switches for telephone-switchboards, and has for its object the provision of structural units of such switches constructed and mounted in the simplest and most durable manner, while at the same time avoiding `disadvantages inherent` in devices of the prior art.

Ithas been the common practice prior to my invention to mount spring-jack switches in convenient units of ten or twenty switches within the body of rubber strips suitably channeled and bored to surround and support substantially the entirel spring-jack. Such construction necessarily is expensive,

.inasmuch as it involves the employment of special machinery and a'high grade of workmanship'for pro erly forming the rubber supporting-strip, w 'ich strip, in addition, is comparatively fragile, particularly when completely bored and grooved to accommodatel the switch parts, and in consequence the damagel or breakage of such strips in the course of manufacture is considerable. These strips of spring-jack switches, moreover, are upon some accounts quite as unsatisfactory to the user. Thethin rubber'walls of the honeycombed strip are very liable to break, particularly when subjected to Vlow temperatures. The strips not infrequently warp out of shape, and accidentalcrossing of the connectedwires with `high-tension conductors sometimes impairs theinsulation ofthe individual spring-jack switches, thus destroying the usefulness `of the entire strip. When subjected to hard service, too, the weakened supportin -strip has been demonstrated not to be sufl'I switch parts sometimes loosening therein and the lugs by which the strips are secured in place becoming wornand broken.

I have accordingly sought to overcome the observed defectsand improve upon this class of switching apparatus in several important particulars specifically pointed out herein and in the appended claims.

cientlyvrigid and substantial, the

The strip of spring-jack switches herein shown embodying my invention may be briefly described as consisting of a supporting or base plate, preferably of aluminium,

along the front and rear edges of which are mountedrelatively narrow strips 'of rubber,

respectively carrying the `test-thimbles and,

the switch-springs of the several jacks. The several switch-springs are peculiarly formed rearwardly with engaging shoulders to insure `their being rigidly, clamped` in position and `alinement in the rear insulating-strip. The inner orcontact springs are stiffened to resist ,fleXure, and the test- Iiimbles and their associated springs are made integral. Shaped mica insulating parts preferably are used between the springs, the shoulders Aprovided thereon similar to those upon the springs preventing the displacement of said insulating parts. y

For more detailed explanation of my improvements I will refer to the accompanying` drawings, illustrating the said embodiment` of my invention, wllerein- Figure l is a plan 'view of an improved` strip of spring-j ack switches, said-strip being partially broken away and dismantled in a manner better illustrating its details of con-y struction. Fig. 2 is a cross-sectional view on line 2 2, Figli. Fiff. 3 is an isometric view of a test-thimble and its integralconnectingspring. Fig. 4 shows a line-spring viewed from above and from the side; and Fig. 5 is a `view of a single spring-jack switch, the three iigures last named being made full size.

The samel letter of reference is em loyed to designate similar parts in each of t e several figures of the drawings.

Upon a plate a, preferably of heavy-gage sheet-aluminium, are mounted the front and rear Strips b c of rubber orj other suitable insulating material. The front strip is provided with a longitudinal shoulder b', against which the plate abuts, and is laterally bored to receive the several test-thimbles d of the spring-jack switches.

I have chosen to show a strip of ten such switches, although double thatnumber may as readily be mounted in the same space, if desired, since' in my improved construction no insulating-walls are interposed between the bodies ofthe several spring-jacks. Hence the individual jacks may be made of somewhat larger size and still be mounted on IOO standard centers, just enabling the outer linespring e when flexed by the inserted plug to lc ear the adjacent switch part.

The front strip b is secured to the plate o by screws b. Ten grooves c are formed in the rear strip c, wherein the assembled switch parts of the several jacks are adapted to be inserted and rearwardly supported, the same forming a rearwardly grooved or channeled mounting-strip for spring-jacks.

Each individual jack comprises two lines rings e f, two contact-springs or anvils e fi?, coaeting therewith, a test-thimble d and its integral connecting spring or part df, and interposed mica insulators g g. All of these preferably are sha ed to afford front and rear abutting shou ders h, (best shown in Figs. 2 and 4,) which engage either side of the insulating-strip c, and a superposed mica strip i, extending the length of the said strip of jacks.

The test-thimbles d, which are stamped out of and suitably shaped, together with their connectings rings d', from' a single piece of sheet meta are inserted in the openings provided in they front strip b.- and secured therein by means of flush-pins d. Said thimbles are slightly countersunk and reamed out to present a uniform bore for the connect ing-plug.

A narrow metal strip lc, placed above the mica strip i, seatsthe screws 7c", which are inserted upon either side of each spring-jack switch, said screws ser-ving to secure the several strips to the platel and binding down the strips i' cto clamp the jacks rigidly in their respective grooves.

The several switch par-ts preferably are stamped from German silver, the engaging springs being provided with platinum contacts, as e f". The line-springs are given an inward set, as see-n in Fig. 4, to insure their normal contact with the coactingV contactfspri-ngs. Said contact-springs e f are formed' of relatively heavy-gage metal and are provided with interposed stiffening-insw laters g to minimize or prevent their flexure by the unequal action of the line-springs durl ing the insertion and removal ofthe connecting-plug- Z. Thisserves at such times to maintain the alinement ofI the said linesprings with the thimble and facilitates the entrance and withdrawal of theplug. The projecting ends d" ofthe plate serve to support the strip of jacks in position upon the switchboard, which may be built u of numerous superposed strips the wef-known manner. The; connecting-wires of the associated conductors in the telephone-exchange are electrically unl-'ted with the several switch parts by soldering said Wires, respectively, to

switch parts.

Mere enplanation of the illustrated structurewlll lnsure full` appreciation of the fact that many disadvantages found in the devices of the art have been eliminated and overcome by my improvements. The strip of springacks is durable and quite cheaply constructed. It will not war out of alinement and is adapted to wit stand the severestservice.

The narrow rubber' insulating-strips are easily constructed, effecting a saving both in vlabor and material over the devices of the prior art. Should said insulating-strips accidentally become cracked or broken, the utility of the completed strip of sprin -jacks will not be impaired, since the meta baseplate a will securely retain the broken porf tions in position. The longitudinal thrust exerted by the plug upon the springs is taken up by the abutting shoulders h and the rear insulating-strip in which said springs are anchored.

The several parts are freely accessible for inspection and repair, and accumulated dust and dirt may be easily removed from the strip. The mica insulation by which the individual springs are electrically separated is practically imperishable and is not impaired by high-tension currents, which sometimes injure jacks mounted between thin rubber insulating parts.

Having new described my impro-ved springjack and the novei manner of mounting the same in strips for use, I claim, together with such modifications thereof as are by law implied, the following:

1. In ay spring-jack switch, the combination with the line-springs ej, of theircoacting contact-springs or anvils e" f", an integral I test-thimble and bowed connecting-spring d d" shaped from a single piece of shee-t metal,

said springs being provided with similar mounting-terminals and closelyassembled in substantially parallelHplanes, and a rearwardly-channeled meuntingstrip wherein all of the parts are mounted, substantially as set forth. I

2. in a strip of spring-jack switches, the

combination withl a relatively narrow strip of' insulating material, the same being chan neled or grooved, of'A separate spring-jack parts mounted within the grooves, compris ing line-springs and a test-thimbleand its connecting-spring, and thin insulating parts disposed therebetween; the said springs and insulating' parts being rearwardly formed with abutting shoulders h adapted te embrace the narrow, insulating, mounting-strip. and secure the several parts of the jacks Within their respectivegrooves, and a, superposed insulating-strip cooperating in retain-- ing the parts` in position, substantially as 125 set forth. the perforated dwerg-ing extremities of said 3. In a spring-jack switch, the combination with the inner contact-springs or anvils, of the long and short line-springs pressingl against said contact-springs. from opposite IIO sides, and a sleeve through which the connecting-plug is inserted to contact with the two line-springs in succession, the said inner contact-springs or anvils being suitably stiffened, and thus adapted to preserve the alinement of the line-springs during the insertion and withdrawal of the plug, substantially as set forth.

l 4. In a strip of spring-jack switches, the combination with a metal base-plate a, of a front strip b having an abutting shoulder b secured along the forward edge of said plate,

a channeled strip c mounted upon its rear edge and a plurality of springjack switches mounted upon said strips b c, said plate and rear strip being firmly secured together upon either side of each of the mounted springjacks, substantially as set forth.

5. In a strip of spring-jack switches, the combination with a flat base-plate a, of narrow front and rear insulating-strips b c mounted along the edges thereof, said strips being respectively bored to receive the testthimbles and grooved to accommodate the rear or mounting portions of the spring-jack switches, and a plurality of springjack switches mounted in the grooves with all the parts thereof upon edge, said switches eX- tending between the said insulating-strips and supported thereby above the level of the base-plate, their body portions being uninclosed and thus made freely accessible, substantially as set forth.

6. In a strip of spring-jacl switches, the combination with an `aluminium plate a, of insulating-strips b c secured along its front and rear edges, the former being bored to receive the test-thimbles and the latter grooved to accommodate and support the rear portions of the several switch parts, a plurality of spring-jack switches carried by said insulating-strips and a superposed and insulated strip k clamping the jacks within the strip c,

said strips and plate being rigidly secured together, substantially as set forth.

7. In a spring-jack switch, the combination with the line-springs e f, of the testthimble and its bowed connecting-spring, spacing-insulators disposed therebetween; all of said parts being provided with similar mounting-terminals and closely assembled in substantially parallel planes, and a rearwardly-channeled supporting-strip wherein all of the parts are mounted, substantially as set forth.

8. In a strip of spring-jack switches, the combination with a metal base-plate a, of a front strip l) secured along the forward edge of said plate, a channeled strip c mounted upon' its rear edge, and a plurality of springjack parts mounted upon the rear strip, said plate and strip being firmly secured together upon either side of each of the mounted spring-jacks, substantially as set forth.

9. In a strip of spring-jack switches, the combination with a mounting-strip of insulating material, the same being grooved or channeled substantially its entire depth to provide mountings for the spring-jack switches, of a plurality of spring-j ack switches respectively mounted in said grooves, and a superposed and insulated strip of metal firmly securing the spring-jack switcheswithin their respective grooves in the mountingstrip; said superposed strip being united with the mounting strip between the grooves and serving also to stay or strengthen the weakened mounting-strip, substantially as set forth.

Signed by me, in the presence of two subscribing witnesses, at Cleveland, Ohio, this 29th day of October, A. D. 1901.

CHARLES H. NORTH. Witnesses:

ELLA M. HrcKs, ALBERT LYNN LAWRENCE. 

